Continuous band forging machine



Dgc. 10, 1968 w. F. LAUENER 3,415,106

CONTINUOUS BAND FORGING MACHINE Filed March 7, 1966 2 Sheets-Sheet l Mllm:

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Dec. 10, 1968 w. F. LAUENER 3,415,106

'CONTINUOUS BAND FORGING MACHINE Filed March 7, 1966 2 Sheets-Shea.

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United States Patent 3,415,106 CONTINUOUS BAND FORGING MACHINE Wilhelm Friedrich Lauener, Langenhard, Zurich, Switzerland, assignor t0 Prolizenz AG, Chur, Switzerland, a corporation of Switzerland Filed Mar. 7, 1966, Ser. No. 532,474 Claims priority, application Switzerland, Mar. 9, 1965, 3,216/65 Claims. (Cl. 72-408) ABSTRACT OF THE DISCLOSURE A machine for the forging of a continuous band has two forging dies driven by two oppositely positioned hydraulic pistons that are oscillated oppositely synchronously by oscillatable plungers driven by eccentric driving means.

The invention relates to the continuous forging of metal bands, for instance of metal bands emerging from continuous casting machines, and relates more particularly to continuous band forging machines that have synchronously oppositely oscillating forging dies.

Continuous band forging machines of the aforesaid type have heretofore become known which can reduce the thickness of a band in a single run that would require several passes during rolling. Machines of this type permit a reduction in thickness of up to 80 percent, thus reducing a metal band to one-fifth of its original thickness in a single run through the machine.

It is among the principal objects of the invention to provide a machine of this type in which the two forging dies are carried by two hydraulically synchronously oppositely oscillated pistons.

It is another object of the invention to provide such a machine in which the driving energy is provided by hydraulic pressure generated from synchronously eccentrically driven plungers operating in plunger chambers that communicate interiorly with the interior of the hydraulic cylinder in which the pistons operate.

It is a further object of the invention to provide such a machine in which there are two pistons and at least two plungers driven from the same shaft in synchronism.

It is still another object of the invention to provide such a machine in which there are arranged two oscillating pistons but four plungers, two plungers being assigned to each piston, and all the plungers being driven with relation from a single drive shaft.

It is still a further object of the invention to provide resilient retracting means for each piston, so that during the return stroke of the plungers the suction pressure of the fluid will be aided in retracting the piston to its position of greatest spacing from the opposite piston.

Further objects and advantages of the invention will be set forth in part in the following specification and in part will be obvious therefrom without being specifically referred to, the same being realized and attained as pointed out in the claims hereof.

In accordance with a preferred embodiment, two sides of the machine which carry each two eccentric drives, two plungers, and two oscillating bearings, with the necessary gaskets, roller bearings or ball bearings, and so forth, are sometimes designated in the following as pulsators.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description, taken in connection with the accompanying drawings, in which:

FIG. 1 is a vertical sectional view of a machine in accordance with the invention; the fluid conduits, valves and pumps have been illustrated only schematically;

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FIG. 2 is a vertical sectional view, taken on the line AA of FIG. 1; and

FIG. 3 is a fragmentary sectional view, taken on the line BB of FIG. 1, and showing the band in the process of being forged (which band, however, had been omitted from FIG. 1).

In carrying the invention into effect in one of the embodiments which has been selected for illustration in the accompanying drawings and for description in this specification, and referring now particularly to FIG. 1, there is provided a machine for the continuous forging of a metal band. The machine comprises two opposite synchronously oscillatable pistons 11. Each piston carries near its inner end, that faces the opposite piston, a forging die 10 that is secured to the piston 11. The pistons 11 are aligned symmetrically opposite each other in the interior of a cylinder 24. Near the outer end of each piston 11, the cylinder 24 defines a pressure chamber 14 in which there is received a pressure fluid. The pressure fluid preferably at the same time acts as a lubricant. Two channels 16 communicate interiorly on one side with the pressure chamber 14 and on the other side each with one plunger chamber 17 of the respective pulsator.

Thus, in accordance with the preferred embodiment shown in FIG. 1, there are provided four plunger chambers 17, into each of which there reaches an elongated plunger 18.

Each plunger 18 is driven from an eccentric driving mechanism 21, and with its outer end projects through an oscillating bearing member 20 into the respective plunger chamber 17 Thus, each plunger 18 performs a longitudi ml and a tilting oscillating motion, and the free end or head of the plunger 18 during its oscillation movement alternatively reduces and, respectively, enlarges its plunger chamber 17.

Each of the four plungers 18 projects diametrically through a bore 19 in the respective oscillating bearing member 26, and is driven by the aforesaid eccentric driving mechanism 21. Each eccentric driving mechanism 21 is energized by a driving shaft 22 that has a fly-wheel 23. The bearing members 20 are journalled for rotation, preferably in the wall of the cylinder 24.

Resilient means are provided for aiding in the retracting of the pistons 11 to the position of maximum spacing apart of the pistons 11. This means comprises a rod 12 that is connected to the outer end of each piston 11 and projects through the cover 13 of the cylinder 24, and is slidably sealed therein. Resilient means are provided, such as a disc type compression spring 15 that engages the cover 13 and a projection formed on the rod. The springs 15 urge the pistons 11 apart.

During rapid operation of the machine, namely rapid succession of stroke of the forging dies, the retracting suction action of the pressure fluid may not suflice to pull apart the forging dies 10 with sufiicient speed. The action of the springs 15 aid in this retraction movement. Instead of the disc type compression springs 15, the resilient means may be helical compression springs or pneumatic or hydraulic means, or the like.

Conventional means are provided (not shown), for instance grooves and keys, for guiding the pistons 11 during their oscillating strokes axially non-rotatably.

In accordance with a preferred embodiment, each plunger chamber 17 has a cylindrical portion 25 in which there is disposed a sealing ring 26. During operation of the machine, the pressure of the pressurized fluid will cause the sealing ring 26 to be pressed towards the bearing member 20 and towards the inner wall of the cylindrical portion 25 of the plunger chamber 17.

In order to synchronize the movement of both pulsators, there is provided a single driving shaft 27 (see FIG.

3 2), that drives both shafts 22 that carry the eccentric driving mechanism 21 for the pulsators.

As best shown in FIG. 1, the upper die may have abutment plates 28 and the lower die 10 may have corresponding abutment plates 29. These abutment plates 28, 29 serve to limit the movement towards each other of the dies 10, and thus assure a uniform thickness of the forged metal band. Preferably, these abutment plates 28, 29 are adjustable on the dies 10.

In order to renew, or to replenish the pressure liquid which may have been decimated by leakage losses, there is provided a conduit that includes a reservoir 48, a pump 36 and in series therewith an overflow valve 40. There is also provided an overflow valve 37 (on the right hand side of FIG. 1). In the illustration of FIG. 1, the pump 36 is connected to ducts 30, 31 and 32, and the connection to the valve 37 is through ducts 33, 34, 35. The ducts 31, 32, 34 and 35 are, preferably by means of bores 41 and 42, connected to the plunger chambers 17. Check valves 38 and 39 are provided to relieve any over-pressure occurring in the ducts 31 and 32 that are pressurized by the pump 36.

Instead of the check valves 38 and 39, a single check valve 54 may be provided in the duct 30 (as indicated in broken lines in FIG. 1).

The operation of the oil conduit is as follows: The pump 36 will supply oil from the reservoir 48 through a filter 49, into the ducts 30, 31 and 32 delivering the oil to the plunger chambers 17 and thence to the pressure chambers 14. The oil emerging from the overflow valves 37 and returns to the reservoir 48 in ducts and 51.

In accordance with a preferred embodiment, a conventional hydraulic accumulator (shown in broken lines in FIG. 1) may be provided in advance of the check valves 38 and 39, and 54; in that event the overflow valve 40 may be dispensed with, as well as the return duct 51; yet, the overflow valve 40 and the return duct 51 may be retained for additional safety. The effect of the accumulator 55 is that under normal operating conditions all the pressure liquid, such as pressure oil that is delivered from the pump 36, will be delivered into the machine; the accumulator renders it possible to use a small pump 36.

Ducts 52 are provided which return to the reservoir 48 oil that has leaked and been accumulated in spaces 53. During operation, such leaking oil must always be present, as the pressure oil also has a lubricating function.

The operation of the above described invention is as follows:

The shaft 27 is rotated, and causes the rotation of the two shafts 22 that carry the eccentric driving mechanism 21. These, in turn, cause the opposite oscillating movements of the plungers which are oppositely arranged in each of the pulsators to the right and to the left of the 0s cillating pistons 11. The oscillating plungers alternately increase and decrease the pressure of the pressure liquid, such as the pressure oil in the intercommunicating plunger chambers 17, channels 16 and pressure chambers 14 for each piston 11, causing the opposite oscillations of the two pistons 11. Due to the opposite arrangements of the plungers 18 and the single driving source provided by the shaft 27, the opposite oscillations of the pistons 11 in the cylinder 24 will be synchronous.

The example shown in FIG. 1 relates to a machine for the forging of a metal band that has a width of 300 mm., and an initial thickness of 20 mm., which thick ness will be reduced down to 4 mm. A machine of this type is used on occasion for the forging reduction of a pre-rolled aluminum band from a thickness of 8 mm. to a thickness of 1.7 mm., which is a reduction of about five to one. The stroke in this example of FIG. 1 of the plungers 18 is 130 mm. The pistons 11 have a diameter of 400 mm. and are hollow and have a wall thickness of 70 mm., and are made of high quality cast iron. The stroke of the pistons 11 is about 6 mm.

The cylinder 24 is made of a steel casting, and the oscillating bearing members 20 form a case hardened steel with brass bushings. The plungers 18 and the eccentric discs are forged in one piece of steel. The ducts 33 through 35 are seamless steel pipes.

As best shown in FIG. 3, the dies 10 are mounted on die holding jaws 43 which are mounted in the bottom sections of the pistons 11. Channels 44 are provided for a cooling fluid, and holding means 45 are arranged for mounting the dies 10. The metal band 46 to be forged moves from right to left in FIG. 3, as indicated by an arrow. As shown in FIG. 3, due to the specific structure of the dies 10, the reducing forging is carried out in steps. The finished forged band is designated 47.

As evident from FIG. 1, the instant invention permits the building of a compact machine that requires little space, and has excellent performance characteristics, free from involuntary stoppages over long periods of operating time.

The frequency of stroke oscillations of the dies 10, owing to the robust construction of the pulsators in accordance with the invention, may be chosen at a high rate, for instance 12 to 25 cycles per second, or more. Consequently, a forging machine of this type may be mounted adjacent a continuous casting machine, for instance a rotary continuous casting machine, or a belt type mold continuous casting machine.

Among the rotary continuous casting machines, the highest casting speed appears to be attainable by that of Hazelett, of about 9 meters per minute at a band thickness of from 9 mm. to 10 mm.; in this case, an oscillating stroke frequency of from 20 to 30 cycles per second would seem to be appropriate, which can easily be obtained with the instant band forging machine.

The instant invention, however, lends itself also for much larger band widths than 300 mm. For bands of a width of 1000 mm., a piston of oval cross section may be chosen that has a large diameter of 1000 mm. and a small diameter of 500 mm., and the piston may be reinforced with radial inner ribs.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

Having thus described the invention, what I claim as new and desire to be secured by Letters Patent, is as follows:

1. In a machine for the forging of a continuous metal band, the combination of two forging dies oscillatable oppositely towards and from each other in synchronism, operating means operable for holding, guiding and driving said dies comprising a hydraulic cylinder, two oppositely positioned pistons movably disposed in said cylinder each carrying near the inner end facing the other a forging die, motor means comprising oppositely oscillatable plungers, at least one plunger chamber defined adjacent each piston and receiving one of said plungers and communicating interiorly with a portion of said cylinder adjacent the outer end of the respective piston therein, whereby oscillating movement of each plunger is transmitted to the respective piston for oscillating the piston, and eccentric driving means in driving connection with said plungers.

2. In a machine, as claimed in claim 1, retracting means for each piston comprising a rod mounted near said outer end to said piston and extending to the interior of said cylinder, and resilient means engaging said rod outside the piston interior and urging said piston into a position of maximum spacing from the opposite piston.

3. In a machine, as claimed in claim 2, said resilient means comprising a spring mounted between said rod and the exterior of the cylinder wall.

4. In a machine, as claimed in claim 1, a bearing for each plunger comprising a bearing member journalled for oscillation on the wall of said cylinder adjacent the plunger chamber about an axis disposed in a plane at right angles to the axis of said cylinder, the plunger extending diametrically through said bearing member and being slidable therein longitudinally of the plunger whereby the plunger will perform relative to the plunger chamber a longitudinal stroke and simultaneously a tilting movement, thereby oscillating said bearing member about its axis, the free forward end of the plunger projecting into the plunger chamber.

5. In a machine, as claimed in claim 4, a sealing ring disposed in each plunger chamber surrounding the forward end of the plunger therein, the pressurized fluid pressing said sealing ring towards the .walls of the plunger chamber and towards said bearing member, for sealing them.

6. In a machine, as claimed in claim 1, and means for synchronously driving all of the plungers and thereby said pistons comprising a single driving shaft driving said eccentric driving means for all the plungers.

7. In a machine, as claimed in claim 1, each of said dies comprising abutment means at both the entrance and the exit ends for the band to be forged, operable to limit the approach of said dies towards each other.

8. In a machine, as claimed in claim 1, and a hydraulic conduit connected with relation to said plunger chambers for delivering pressure fluid thereto forreplenishment, said conduit further comprising a pump and an overflow valve in series with said pump.

9. In a machine, as claimed in claim 8, said conduit comprising ducts connecting said pump and overflow valve with said plunger chambers.

10. In a machine, as claimed in claim 9, said ducts having each a check valve.

References Cited UNITED STATES PATENTS 1,206,193 11/1916 Bates 72-453 2,232,889 2/1941 Spencer 72408 CHARLES W. LANHAM, Primary Examiner.

G. P. CROSBY, Assistant Examiner.

US. Cl. X.R. 

